How to find which permalinks are still being reserved and how to purge (safely)

Hi,

I’ve noticed that I have some old permalinks being redirected to 303, and I’d like to use some of them as they were media files I deleted a few dats ago, but I want to reuse those same filenames. I made sure there is nothing in that directory with that same file, but once I upload the new one, the display image is always the old one. I clear the cache (I have a plugin for that), I double checked via FTP that the files are correct, but I just can’t get the new file to appear on my blog, even if I go via direct link.

How can I fix this? How can I find all of those annoying old permalinks that are not being used anywhere and just purge them?

I used a plugin to purge old slugs, but that only works for blog posts…

The page I need help with: [log in to see the link]